<template>
	<div class="count">
		<h2>当前求和为：{{sum}}</h2>
		<!-- v-model的三个修饰符 -->
		<!-- <input type="text" v-model.number="n"> -->
		<!-- <input type="text" v-model.trim="n"> -->
		<!-- <input type="text" v-model.lazy="n"> -->
		
		<select v-model.number="n">
			<option value="1">1</option>
			<option value="2">2</option>
			<option value="3">3</option>
		</select>
		<button @click="increment">+</button>
		<button @click="decrement">-</button>
		<button @click="incrementOdd">当前和为奇数再加</button>
		<button @click="incrementWait">等一等再加</button>
	</div>
</template>

<script>
	export default {
		name:'Count',
		data() {
			return {
				n:1,
				sum:0
			}
		},
		methods: {
			increment(){
				this.sum += this.n
			},
			decrement(){
				this.sum -= this.n
			},
			incrementOdd(){
				if(this.sum % 2){
					this.sum += this.n
				}
			},
			incrementWait(){
				setTimeout(()=>{
					this.sum += this.n
				},1000)
			}
		},
	}
</script>

<style scoped>
	.count{
		background-color: orange;
		padding: 20px;
	}
	button{
		margin-left: 10px;
	}
</style>